Thank you for viewing. The casting has no burrs, and the inner and outer edges are chamfered. One side has a polished finish, and the other side has a hairline finish, allowing you to choose the anti-loosening effect by the direction of installation. It can be used on snare drums, toms, and bass drums. Here are some comments from users who have purchased it: ① Improved sound quality with better projection and clarity. ② Harmonics became pleasant, and the instrument itself resonated better. ③ Added beautiful high frequencies, resulting in usable sound. ④ The washer itself has high density and mass, which positively impacts the sound. ⑤ Open and closed rimshots feel great. ⑥ The "tenacity" of the material makes tension bolts less likely to loosen even with hard hits. ⑦ Compared to brass washers from multiple manufacturers, this one is the best made. ⑧ It's also appreciated that it fits Sonor's countersunk bolts and rod diameters. And so on, we have received many comments. Brass has excellent acoustic properties and is used in guitars and basses for sustain blocks, saddles, bridge bodies, tuning pegs, nuts, etc. For drums, the sound impact of brass hoops and washers is imagined to be one of the reasons why vintage instruments like the 60s Super Ludwig and Radio King are preferred. Due to the current global price surge of copper, the main raw material, we kindly ask that you refrain from requesting price reductions. Please note that this product is made to order after purchase, so please allow time for shipping. Thank you.